Question

A test has a mean of 65 with standard deviation of 5. What percent of the

students would you expect to receive a grade of 60 or less?

Answer 1

16%

Explanation:

The test has a mean of 65 with standard deviation of 5.

We want to find the percent of the

students we expect to receive a grade of 60 or less.

We can use the empirical rule to solve this question.

According to the Empirical rule , 68% within one standard deviation.

This means that 68% fall within one standard deviation below and above.

Hence just one standard deviation below will 34%. (60 to 65).

Therefore the percentage falling below 60 will be 50%-34%=16%